Digital holographic interferometry in a disturbed environment
Digital holographic interferometry is an optical measurement technique that is capable of measuring the movement/deformation of an object surface with extremely high accuracy, spatial resolution and temporal resolution. But, because it is very sensitive to disturbances, it is mostly used in well con...
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Luleå tekniska universitet, Strömningslära och experimentell mekanik
2009
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ftluleatu:oai:DiVA.org:ltu-17852 2023-05-15T17:09:07+02:00 Digital holographic interferometry in a disturbed environment Lycksam, Henrik 2009 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17852 eng eng Luleå tekniska universitet, Strömningslära och experimentell mekanik Luleå Licentiate thesis / Luleå University of Technology, 1402-1757 http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17852 urn:isbn:978-91-7439-000-1 Local 58799160-a44e-11de-8293-000ea68e967b info:eu-repo/semantics/openAccess Applied Mechanics Teknisk mekanik Licentiate thesis, comprehensive summary info:eu-repo/semantics/masterThesis text 2009 ftluleatu 2022-10-25T20:50:46Z Digital holographic interferometry is an optical measurement technique that is capable of measuring the movement/deformation of an object surface with extremely high accuracy, spatial resolution and temporal resolution. But, because it is very sensitive to disturbances, it is mostly used in well controlled laboratory environments. An exciting new application of the method could be for process supervision in the manufacturing industry. But before it can be used in such an environment it must be made more insensitive to disturbances. The work in this thesis deals with post processing of data from holographic interferometry measurements to reduce the effects of mechanical vibrations and random refractive index fluctuations in the surrounding air. The first approach of using a purely temporal interference filter was successful in reducing the noise due to vibrations, but the noise from the air disturbance was only reduced over a very limited spatial region. A more complete spatio-temporal filter that is not of the interference type requires that the spatio-temporal statistics of the noise from the air can be measured. Therefore the rest of the work is devoted to this problem. The method developed is applied to the relatively simple case of locally homogenous/isotropic refractive index fluctuations generated in a small wind tunnel. There is a simple theory for these types of fluctuations for which the method was successfully verified. Godkänd; 2009; 20090918 (henlyc); LICENTIATSEMINARIUM Ämnesområde: Experimentell mekanik/Experimental Mechanics Examinator: Professor Mikael Sjödahl, Luleå tekniska universitet Tid: Torsdag den 15 oktober 2009 kl 10.00 Plats: E 1024, Luleå tekniska universitet Master Thesis Luleå Luleå Luleå University of Technology Publications (DiVA) |
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Luleå University of Technology Publications (DiVA) |
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language |
English |
topic |
Applied Mechanics Teknisk mekanik |
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Applied Mechanics Teknisk mekanik Lycksam, Henrik Digital holographic interferometry in a disturbed environment |
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Applied Mechanics Teknisk mekanik |
description |
Digital holographic interferometry is an optical measurement technique that is capable of measuring the movement/deformation of an object surface with extremely high accuracy, spatial resolution and temporal resolution. But, because it is very sensitive to disturbances, it is mostly used in well controlled laboratory environments. An exciting new application of the method could be for process supervision in the manufacturing industry. But before it can be used in such an environment it must be made more insensitive to disturbances. The work in this thesis deals with post processing of data from holographic interferometry measurements to reduce the effects of mechanical vibrations and random refractive index fluctuations in the surrounding air. The first approach of using a purely temporal interference filter was successful in reducing the noise due to vibrations, but the noise from the air disturbance was only reduced over a very limited spatial region. A more complete spatio-temporal filter that is not of the interference type requires that the spatio-temporal statistics of the noise from the air can be measured. Therefore the rest of the work is devoted to this problem. The method developed is applied to the relatively simple case of locally homogenous/isotropic refractive index fluctuations generated in a small wind tunnel. There is a simple theory for these types of fluctuations for which the method was successfully verified. Godkänd; 2009; 20090918 (henlyc); LICENTIATSEMINARIUM Ämnesområde: Experimentell mekanik/Experimental Mechanics Examinator: Professor Mikael Sjödahl, Luleå tekniska universitet Tid: Torsdag den 15 oktober 2009 kl 10.00 Plats: E 1024, Luleå tekniska universitet |
format |
Master Thesis |
author |
Lycksam, Henrik |
author_facet |
Lycksam, Henrik |
author_sort |
Lycksam, Henrik |
title |
Digital holographic interferometry in a disturbed environment |
title_short |
Digital holographic interferometry in a disturbed environment |
title_full |
Digital holographic interferometry in a disturbed environment |
title_fullStr |
Digital holographic interferometry in a disturbed environment |
title_full_unstemmed |
Digital holographic interferometry in a disturbed environment |
title_sort |
digital holographic interferometry in a disturbed environment |
publisher |
Luleå tekniska universitet, Strömningslära och experimentell mekanik |
publishDate |
2009 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17852 |
genre |
Luleå Luleå |
genre_facet |
Luleå Luleå |
op_relation |
Licentiate thesis / Luleå University of Technology, 1402-1757 http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17852 urn:isbn:978-91-7439-000-1 Local 58799160-a44e-11de-8293-000ea68e967b |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766065048102371328 |